Mechanical adjustment of elements



Mardi 9, 1948. c. H; FoULKEs Re. 22,982

MECHANICAL ADJUSTMENT OF ELEMENTS MOUNTED INSIDE VACUUM TUBES OriginalFiled Aug. 16. 1943 .adjusting yfrom me pettine "side the tube, and 'aRessued Mar. '9, 194,8

MoHANrcAL ADJU STMENT OF ELEMENTS MOUNTED INSIDE VACUUM TUBEScii'fris't'oher Henry Foulkes, Lehnen, Enia'hj s:

signor .to Standard Telephones 'a d C Limited, London, England, aBritish ni'piy original No. 2,368,821, `ama February ge, zi-Isis,

Serial No. 498,802, August ,16,` 1343. AApplication for reissue Februav` The 'present invention relates to means for electrodes or otherYelements mounted inside rvacuum or gas-filled tubes.

It frequently happens that `a member or element x'efd inside a Itubeisr'equir'd to be adjusted from time to vtime as regards its positionwith lrespect to other elements. There are considerable difficulties indevisingany satisfactory mechanical adjustment vfr m 'outside and whichat the same time will nfotcaus'e a vdeterioration of Athe, vacuumfor`changes :in pressure in agasll'ed tube) Magnetic mansare of courseknown for adjusting elementsdinside tubes but these are not alwayspracticable and generally lack precision. ,Y l, i

In the present,n invention, the dilculties are overcome vby providing"an 'arrangement for adjusting the position of an elementmounted insidea vacuum or f'gas-'lledtube comprising an elastic metal pipe sealedthrough the envelope of the tube with a gas-tightise'alfand extendingout'- m'etal rod which passes through the pipe into the envelope and issecured to the pipe only at the extremity of the external extensionmaking a gas-tight joint therewith.

The invention will be described with reference to the accompanyingdrawing. in which:

Figure 1 is a vertical central section through one embodiment. and

Figure 2 is a similar view of a modication of Figure 1.

It will be understood that the problem is the same whether the tubeconcerned'is exhausted or is filled with gas at some prescribedpressure, and accordingly the term tube will be used in thisspecification to signify a. vacuum tube or a gas-filled tube.

Fig. 1 shows the stem portion I of a tube which portion will ultimatelybe sealed to the remainder of an appropriate bulb or envelope, notshown. This stem is preferably made of a lead glass and comprises are-entrant portion 2 to which is sealed a copper cup member 3 having afeathered edge adapted for sealing to the glass according to well knownprinciples. Through the base of the `cup is soldered at I a thin elasticmetal pipe 4. A slightly smaller metal rod 5 of any length passesthrough the pipe 4 and through the cup 3 into the envelope and issoldered to the pipe at the outer end 6 only. The two soldered jointsshould, of course, be gas-tight and are preferably made with silversolder.

The upper annular ridge of the stem I carries Great Brit 1r .5. 1947.SrilfNbain November 25,1942 '7 claims. (cl. 2501275) tion can be incand 0.005" thick.V AThe roes 0.062 in diameter, 'for made in this"w`ay'will enable the 'rod lV5 us not-of tcourse,

y, p Y furnis, but it Vhas been found, forfexampl'e, that iff theportion of the pipe j4 which'extends side "the `lvenvelope iis 4 incheslong, th be rotated through 15 degrees on either rside oi a'the "iha'nposition,

, tim

and maybe operated hnHre'dsany sign of loss of vacuum `r ure. It will beevident that ith )perni e angle of rotav Y' ea des reii'by suitablydesigning lthe 'partsgfbrex pipe 4, or in other ways.

The inner end of the rod 5 is suitably connected to the element (notshown) which has to be adjusted inside the envelope. This element might,for example, be the rotating vanes of a condenser, or any other devicewhich has to be rotated. It will be understood, however, that the rod 5,by means of a suitable mechanical linkage, could be adapted to adjust anelement which does not necessarily rotate.

It will be evident also that the rod 5 must be provided either inside oroutside the tube with a suitable friction brake or the like (not shown)so that it will be held in any operated position.

Fig. 2 shows another form of the invention in which the torque is takenup entirely between the rod and the metal cup member sealed to theglass, so that the stem is relieved from all strain. In this case thecup member Il is more heavily made, and has a downwardly extendinghollow cylindrical portion I2 which forms the main support of the tube.The portion I2 may be secured in any way to a panel or other fixed partshown conventionally dotted at I3. This may carry a scale plate I4, anda pointer I5 may be attached to the rod 5 to indicate the angle ofrotation on the scale. Any suitable like .arrangement may obviously beused.

causa be ribbed or fluted and have a cross section resembling a daisy/orthe like Yradial petals. Furthermore, if a pipe having this type ofcross section be formed with a twist so `that it becomes like, amultiple helix, greater angles of twist become possible, combined at thesame time with a longitudinal movement of the rod.

What is claimed is:

1. A sealed electronic tube having a glass stem portion, a rotatablyadjustable sealed mounting for adjusting the position oi' an elementcoupled to said mounting within said tube comprising a flexible metalmember having a sealed connection to the stem portion and a solidadjusting member extending through and sealed to the iiexible memberadjacent the outer end thereof, the ilexible metal member having a thincircumferential wall portion torsionally deformable by rotation of theadjusting member to provide rotary adjustment of the mounting.

2. An adjustable mounting as set forth in claim -1, in which the metalmember comprises a tubular metal element surrounding the solidadjustingmember, mounted at one end on the glass stem portion andconnected at the other end to the adjusting member. f f f 3. A sealedelectronic tube having a glass stem vportion with a reentrant section, arotatably adjustable sealed mounting comprising a flexible metal memberhaving a sealed connection to said 4reentrant section of the stemportion, said mem- 'ber including a flexible tubular element, and anelongated solid adjusting member extending axially through said tubularelement and sealed to said element adjacent the outer end thereof, theflexible member having a thin circumferential wall portion torsionallydeformable by rotation of the adjusting member to provide rotaryadjust-- ment of the mounting.

4. YA sealed. electronic portion, an adjustable sealed mountingcomprising a flexible metal member having a sealed conwith a number of'nection to the stem portion, said member including a iiexible tubularelement, and an elongated solid adjusting member extending axially fthrough saidv tubular element and sealed to said element adjacent theouter end thereof, said stem portion comprising a re-entrant centralsection and an annular dependent skirt sealed to said section, saidiiexible metal member having a sealed connection to said skirt.

5. A base construction for a sealed electronic tube comprising a glassstem portion and an adjustable sealed mounting including a flexiblemetal member having a sealed connection to the stem portion, said memberincluding a cupshaped support and a flexible tube connected at its innerend to said support, and an adjusting rod extending through said tubeand sealed to the outer portion of the tube.

6. An adjustable claim 1 in which the flexible member comprises atorsionally deformable metal tube having side walls that aresubstantially straight and longitudinally incompressible in a directionparallel to the metal tube axis.

7. A base construction for a sealed electronic tube comprising a glassstem portion and an adinstable sealed mounting including a flexiblemetal member having a sealed connection to the stem portion, said memberincluding a cupshaped support having a dependent tube support mountedthereon and a flexible tube connected at its inner end to saidcup-shaped support, and an adjusting rod ible tube and sealed to theouter portion thereof.

. v tube having a glass stem` CHRISTOPHER HENRY FOULKES.

REFERENCES CITED UNITED STATES PATENTS v Name Gunn Number Date Feb. 20,1940 mounting as set forth in y extending through said fiex-

